Pipelines include one or more carrier pipes that carry fluids such as oil and natural gas from a source point to an end point. Pipelines can be very long and occasionally must extend through bores in the ground to avoid obstacles such as infrastructure improvements, buildings, bodies of water, etc. One technique for forming bores is horizontal directional drilling. Forming suitable bores can be expensive. To limit drilling costs, multiple carrier pipes in a pipeline can be installed together as a group in the same bore. A more expensive alternative is to drill separate bores for each carrier pipe. An advantage of drilling separate bores for each carrier pipe is that conventional cathodic protection systems can be used without adverse cathodic shielding that typically occurs when cathodically protected pipes are bundled together in a single bore.